Systems and methods to control auxiliary power output voltage using a welding output voltage

ABSTRACT

Systems and methods to control auxiliary power output voltage using a welding output voltage are disclosed. An example power system includes an engine, a generator to provide electrical power based on mechanical power received from the engine, the electrical power comprising welding-type power and non-welding power, and a controller to control the generator or the engine to increase or decrease a voltage of the non-welding power based on a voltage measurement of the welding-type power.

RELATED APPLICATIONS

This patent claims priority to U.S. patent application Ser. No.15/431,966, filed Feb. 14, 2017, entitled “Systems and Methods toControl Auxiliary Power Output Voltage Using a Welding Output Voltage,”and to U.S. Provisional Patent Application Ser. No. 62/329,300, filedApr. 29, 2016, entitled “Systems and Methods to Control Auxiliary PowerOutput Voltage Using a Welding Output Voltage.” The entirety of bothU.S. patent application Ser. No. 15/431,966 and U.S. Provisional PatentApplication Ser. No. 62/329,300 are incorporated herein by reference.

BACKGROUND

Conventional engine-driven power systems provide welding output and anauxiliary (e.g., non-welding, general purpose) power output. Forconstant field, current controlled engine-driven generators, theauxiliary power output voltage of the generator decreases as the load onthe generator is increased. Conventional power regulation methodsattempt to maintain the auxiliary power voltage at a substantiallyconstant voltage.

SUMMARY

Systems and methods to control auxiliary power output voltage using awelding output voltage are provided, substantially as illustrated by anddescribed in connection with at least one of the figures, as set forthmore completely in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatical overview of a work vehicle in which a servicepack in accordance with aspects of this disclosure is installed.

FIG. 2 is a flowchart illustrating example machine readable instructionswhich may be executed to implement the control circuitry of FIG. 1 toregulate an auxiliary power voltage of a service pack based on a weldpower open circuit voltage of the service pack.

FIG. 3A is a block diagram of an example redundant protection circuit toprovide overvoltage and/or reverse polarity detection to an auxiliary DCoutput port.

FIG. 3B is a block diagram of an example redundant protection circuit toprovide overvoltage and detection to a welding output port.

FIG. 4 is an example truth table for the polarity detector circuits ofFIG. 3A.

FIG. 5 is an example truth table for the overvoltage detector circuitsof FIG. 3A.

FIG. 6 is an example truth table for the weld voltage detector of FIG.3B.

FIGS. 7A, 7B, and 7C show a flowchart representative of example machinereadable instructions which may be executed to implement the controlcircuitry of FIG. 1 to automatically control a battery charger circuit.

FIG. 8 is a flowchart illustrating example machine readable instructionswhich may be executed to implement the control circuitry of FIG. 1 tocontrol a generator field current.

FIGS. 9A and 9B illustrate example functions of multiple-function LEDsthat may be used on the service pack of FIG. 1 to provide information toan operator with a reduced number of LEDs.

DETAILED DESCRIPTION

Conventionally, auxiliary power regulation methods are based on usingvoltage feedback from the auxiliary power output. To accomplish voltageregulation using the auxiliary voltage feedback, a high voltage ACsignal is provided to the control board. The high voltage AC signal isisolated from other components on the board that are operating at lowervoltages, such as by maintaining a minimum distance between the highvoltage signals and the lower voltage signals. Such techniques requireadditional board space and connections.

Disclosed examples allows the control of an engine driven generatorauxiliary power output by regulating the auxiliary power output voltagebased on voltage feedback from a welding output when there is no weldload applied.

Some disclosed examples control an open circuit peak voltage of the weldcircuit to on single phase welders, so that the open circuit peakvoltage cannot exceed a threshold voltage level (e.g., 113 V). In somesuch examples, the open circuit peak voltage control is limited usingthe weld voltage feedback, so that the open circuit peak voltage on theweld output remains below the threshold voltage level.

Welding-type power, as used herein, refers to power suitable forwelding, plasma cutting, induction heating, air carbon-arc cuttingand/or gouging (CAC-A), cladding, and/or hot wire welding/preheating(including laser welding and laser cladding).

Welding-type system, as used herein, includes any device capable ofsupplying power suitable for welding, plasma cutting, induction heating,CAC-A and/or hot wire welding/preheating (including laser welding andlaser cladding), including inverters, converters, choppers, resonantpower supplies, quasi-resonant power supplies, etc., as well as controlcircuitry and other ancillary circuitry associated therewith.

Disclosed example power systems include an engine, a generator toprovide electrical power based on mechanical power received from theengine, and a controller. In the examples, the electrical power includeswelding-type power and non-welding power. In the examples, thecontroller controls the generator or the engine to increase or decreasea voltage of the non-welding power based on a voltage measurement of thewelding-type power.

In some examples, the controller decreases the voltage of thenon-welding power when the voltage measurement of the welding-type powerexceeds a first threshold. Some such examples further include anovervoltage protection circuit to disable at least one of thewelding-type power or the non-welding power when the voltage measurementexceeds a second threshold, where the second threshold is a highervoltage than the first threshold. In some such examples, the overvoltageprotection circuit includes redundant circuits configured to selectivelydisconnect a welding-type output or a non-welding type output from thegenerator.

Some disclosed example power systems further include a voltage sensor tomeasure an open circuit voltage for a welding-type output and to providethe open circuit voltage to the controller as the voltage measurement ofthe welding-type power. In some examples, the controller controls thegenerator to increase the voltage of the non-welding power by increasinga field current of the generator. In some examples, the controllercontrols the generator to decrease the voltage of the non-welding powerby decreasing a field current of the generator.

In some example power systems, the controller controls the generator orthe engine to increase or decrease the voltage of the non-welding powerwhen a welding-type output is not providing the welding-type power. Someexample power systems further include an overvoltage protection circuitto disable at least one of the welding-type power or the non-weldingpower when the voltage measurement exceeds a threshold. In someexamples, the welding-type power and the non-welding power areconfigured to receive power via a same field winding in the generator.

Disclosed example methods involve providing non-welding electricaloutput from an engine-powered electrical generator to an output device,measuring a voltage of a welding-type output provided by the electricalgenerator, and controlling the generator or the engine, using a controlcircuit, to increase or decrease a voltage of the non-welding outputbased on the voltage measurement of the welding-type output.

In some examples, controlling the generator or the engine involvesdecreasing the voltage of the non-welding output when the voltagemeasurement of the welding-type output exceeds a first threshold. Somesuch examples further involve disabling, using one or more circuits, atleast one of the welding-type output or the non-welding output when thevoltage measurement exceeds a second threshold, where the secondthreshold is a higher voltage than the first threshold. In someexamples, disabling the at least one of the welding-type output or thenon-welding output involves selectively disconnecting, via the one ormore circuits, the welding-type output or the non-welding type outputfrom the generator.

In some examples, measuring the voltage of the welding-type outputinvolves measuring an open circuit voltage of the welding-type outputand providing a signal representative of the open circuit voltage to acontrol circuit as the voltage measurement of the welding-type power.Some example methods further involve controlling the generator toincrease the voltage of the non-welding output by increasing a fieldcurrent of the generator. Some example methods further comprisinginvolve controlling the generator to decrease the voltage of thenon-welding output by decreasing a field current of the generator.

Some example methods further involve disabling at least one of thewelding-type output or the non-welding output when the voltagemeasurement exceeds a threshold. In some examples, providing thenon-welding output involves providing electrical power for thenon-welding output from a same field winding in the generator as thewelding-type output.

Disclosed example power systems include an engine, a generator, abattery charge circuit, and a controller. The generator provideselectrical power based on mechanical power received from the engine,where the electrical power includes welding-type power and non-weldingpower. The battery charge circuit conditions the non-welding power. Thecontroller controls the battery charge circuit. Without interventionfrom the user, the controller controls the battery charge circuit tooperate in a crank assist mode in response to (i) detecting that adifference between a commanded battery charge voltage and a voltageoutput by the battery charge circuit is at least a threshold voltagedifference and (ii) detecting that a field current in the generator isat least an upper threshold field current. Without intervention from theuser, the controller controls the battery charge circuit to operate in aboost mode in response to (i) detecting that the difference between thecommanded battery charge voltage and the voltage output by the batterycharge circuit is at least a threshold voltage difference and (ii)detecting that the field current in the generator is between the upperthreshold field current and a lower threshold field current.

In some examples, the controller controls the battery charge circuit toincrease an output current of the non-welding power during the crankassist mode. In some such examples, the controller is to, withoutintervention from the user, disables the battery charge circuit when thebattery charge circuit is in the crank assist mode for at least athreshold time. In some example power systems, the controller controlsthe battery charge circuit to increase an output voltage of thenon-welding power during the boost mode. In some examples, thecontroller, without intervention from the user, controls the batterycharge circuit to operate in a trickle charge mode in response (i) todetecting that a difference between a commanded battery charge voltageand a voltage output by the battery charge circuit is less than thethreshold voltage difference and (ii) detecting that the field currentin the generator is less than the lower threshold field current. In somesuch examples, the controller, without user intervention, disables thebattery charge circuit when the battery charge circuit is in the tricklemode for at least a threshold time.

In some examples, the controller, when a battery voltage of a batteryconnected to the battery charge circuit has at least a threshold voltageand a predetermined polarity, enables the battery charger circuit tocharge the battery. In some example power systems, the controller, whena battery voltage of a battery connected to the battery charge circuithas less than a threshold voltage or does not have a predeterminedpolarity, disables the battery charger circuit. In some examples, thecontroller disables the battery charge circuit in response todetermining that a field current in the generator satisfies a thresholdcurrent and that an output voltage is greater than a battery referencevoltage of a battery connected to the battery charge circuit.

Disclosed example power systems include an engine, a generator, abattery charge circuit, and a controller. The generator provideselectrical power based on mechanical power received from the engine,where the electrical power includes welding-type power and non-weldingpower. The battery charge circuit conditions the non-welding power. Thecontroller to controls the battery charge circuit. Without interventionfrom the user, the controller controls the battery charge circuit tooperate in a crank assist mode in response to (i) detecting that adifference between a commanded battery charge voltage and a voltageoutput by the battery charge circuit is at least a threshold voltagedifference and (ii) detecting that a field current in the generator isat least an upper threshold field current. Without intervention from theuser, the controller controls the battery charge circuit to operate in atrickle charge mode in response to (i) detecting that the differencebetween the commanded battery charge voltage and the voltage output bythe battery charge circuit is less than the threshold voltage differenceand (ii) detecting that the field current in the generator is less thanthe lower threshold field current.

Disclosed example power systems include an engine, a generator, abattery charge circuit, and a controller. The generator provideselectrical power based on mechanical power received from the engine,where the electrical power includes welding-type power and non-weldingpower. The battery charge circuit conditions the non-welding power. Thecontroller to controls the battery charge circuit. Without interventionfrom the user, the controller controls the battery charge circuit tooperate in a trickle charge mode in response to (i) detecting that adifference between a commanded battery charge voltage and a voltageoutput by the battery charge circuit is less than a threshold voltagedifference and (ii) detecting that a field current in the generator isless than a lower threshold field current. Without intervention from theuser, the controller controls the battery charge circuit to operate in aboost mode in response to (i) detecting that the difference between thecommanded battery charge voltage and the voltage output by the batterycharge circuit is at least the threshold voltage difference and (ii)detecting that the field current in the generator is between an upperthreshold field current and the lower threshold field current.

Disclosed example non-transitory machine readable storage media includeor store machine readable instructions. The instructions, when executed,cause a processing circuit to initialize an engine-driven generator toprovide electrical power based on mechanical power received from theengine, the electrical power comprising welding-type power andnon-welding power. The instructions also cause the processing circuit tocontrol a battery charge circuit to operate in a crank assist modewithout intervention from a user and in response to (i) detecting that adifference between a commanded battery charge voltage and a voltageoutput by the battery charge circuit is at least a threshold voltagedifference and (ii) detecting that a field current in a generator is atleast an upper threshold field current. The instructions also cause theprocessing circuit to control the battery charge circuit to operate in aboost mode without intervention from the user and in response to (i)detecting that a difference between a commanded battery charge voltageand a voltage output by the battery charge circuit is at least athreshold voltage difference and (ii) detecting that the field currentin the generator is between the upper threshold field current and alower threshold field current. In some examples, the instructions causethe processing circuit to, without intervention from the user, controlthe battery charge circuit to operate in a trickle charge mode inresponse to (i) detecting that a difference between a commanded batterycharge voltage and a voltage output by the battery charge circuit isless than the threshold voltage difference and (ii) detecting that thefield current in the generator is less than the lower threshold fieldcurrent.

A block diagram of an engine driven inverter based power system 100 isshown in FIG. 1 , where the thick black lines indicate powertransmission, and the thin lines indicate control or feedback signals.Power system 100 includes an engine 102, a generator 104, an aux poweroutput 105, a rectifier 106, a converter 108, a controller 110, and awelding output 112. Generally speaking, engine 102 is a gas or dieselpowered engine (a primary mover) that drives a shaft on which a rotor ofgenerator 104 is mounted. Any engine suitable for the desired poweroutput may be used, such as a diesel engine or gasoline engine.

Generator 104 may be a conventional generator having a rotor and stator,and, in the preferred embodiment, is designed by using a single phasegenerator. Additionally or alternatively, the generator 104 may havethree phase windings. The rotor is magnetically coupled with the stator,and a field current is supplied such that when the rotor is turned, anAC output current is produced.

The electrical output of generator 104 is provided to power conditioningcircuitry, including a rectifier 106 and a converter 108. The rectifier106 produces rectified dc power. The rectified dc power is provided toconverter 108, which includes, in the preferred embodiment, at least oneenergy storage device such as a capacitor 107 for smoothing the ripplein the rectified signal to provide a dc bus. In some other examples, adc generator is used instead of ac generator 104 and rectifier 111, therectifier 111 may be part of generator 104, and/or the rectifier 111 maybe between the generator 104 and the converter 108.

The converter 108 also includes an inverter 109 and rectifier 111 thatconvert the smoothed and rectified dc signal to a welding output (havingan appropriate current and voltage). Converter 108 is in the preferredembodiment, a series resonant converter that inverts the dc bus and anoutput rectifier to produce a dc welding current as the welding output112. An ac output is used in an alternative embodiment. An exampleseries resonant converter is described in detail in U.S. patentapplication Ser. No. 08/584,412, the entirety of which is incorporatedherein by reference.

As described in application Ser. No. 08/584,412, a power control circuit113 is included in converter 108 such that the welding current isselected by the operator, and the converter provides the desiredcurrent. Other control functions are also included, such as a hot startand a protection system.

The example converter 108 may support a wide range of welding processes.For example, the converter 108 may provide a pulse spray weld processmay be performed, a short arc, spray CV, spray CC, CC stick, CC TIG,pulse MIG, and/or pulse TIG, among others. These process may beperformed using the power system 100.

The converter 108 is a switched circuit that converts an ac or dc inputto a different ac or dc output. An inverter, as used herein, is aswitched circuit having a dc input and provides an ac output, or onethat has an ac input and a rectifier to produce a dc signal that is thenswitched to produce an ac output that may. Also, as used herein, aninverter may include an output rectifier to produce a dc output.

The controller 110 is provided to control the engine 102 and/or thegenerator 104 in response to feedback 115 from the welding output 112.Feedback, as used herein, includes a signal indicative of or responsiveto an output or intermediate signal, which is provided to the controller110 and which control decisions are made in response thereto. Examplefeedback signals 115 include any welding operating parameter, such ascurrent, voltage, frequency, power, ripple current, ripple magnitude,ripple voltage, ripple frequency, and/or functions and/or derivatives ofthese measures. The specific parameter feedback may be mathematicallyoperated on as required by the control scheme.

Specifically, in some examples, the controller 110 includes a feedbackcircuit 114 that is connected to the welding studs to obtain a weldingcurrent and welding voltage feedback signal. The feedback circuit 114may be included in and/or separate from the controller 110. Thecontroller 110 may be on the same circuit board as the control circuit113 or separate from the controller 110. In some examples, thecontroller 110 is part of the control circuit 113 to share feedbacksignals.

The controller 110 uses the feedback signal 115 to, among other things,determine the input power needed by converter 108, determine whether awelding peak voltage is approaching a fault condition, and/or to controlan auxiliary output power from the auxiliary output 105. In response,the controller 110 controls a speed of engine 102 and/or a field currentof the generator to provide that needed power. Generally, an enginespeed control is controlling the speed of the engine, which controls thepower output of the generator. The controller 110 causes engine 102 tooperate at either an idle speed, or a run speed (close to or at fullthrottle). A solenoid may be used to move the run/idle lever to thedesired position. Alternatively, more than two positions (run/idle) or acontinuous range of positions may be selected, based on the powerneeded. In other examples, the controller 110 controls one or more of athrottle position, a fuel pump, an injection timer, a fuel to air ratio,fuel consumption and/or ignition timing.

The controller 110 includes a combination of one or more circuits, aswell as firmware and software configured to monitor operation of theengine 102, the generator 104, and the power conditioning circuitry 106,108, as well as certain loads in specific applications. Portions of thecontroller 110 may be centrally located as illustrated, or the circuitrymay be divided to control the engine, generator and power conditioningcircuitry separately. In most applications, however, such separatedcontrol circuits may communicate with one another in some form tocoordinate control of these system components. The controller 110 iscoupled to an operator interface 117. In most applications, the operatorinterface 117 will include a surface-mounted control panel that allows asystem operator to control aspects of the operation and output, and tomonitor or read parameters of the system operation. In a weldingapplication, for example, the operator interface 117 may allow theoperator to select various welding processes, current and voltagelevels, as well as specific regimes for welding operations. These arecommunicated to the controller 110, which itself comprises one or moreprocessors 118 and support memory 119. Based upon the operatorselections, then, the controller 110 will implement particular controlregimes stored in the memory via the processors. Such memory may alsostore temporary parameters during operation, such as for facilitatingfeedback control.

The auxiliary power 105 may include DC power and/or AC power for generalpurpose and/or specialized applications. In examples in which the powersystem 100 is configured on a work truck, the auxiliary power 105 mayprovide 12V and/or 24V DC power to, among other things, enable chargingof automotive batteries or the like. Additionally or alternatively, theauxiliary power 105 may provide 110V and/or 230V AC power to enable thepower system 100 to provide power to devices having standard outletplugs. The operator interface 117 may control the controller 110 toconfigure the type(s) of power output by the auxiliary power 105. Thecontroller 110 may then control the generator 104 and/or any powerconditioning circuitry to provide the power selected via the operatorinterface.

In the example of FIG. 1 , the auxiliary power 105 in the power system100 is obtained from a same field winding in the generator 104 as thewelding output. As a result of using a same field winding, the weldvoltage droops when the auxiliary power 104 is loaded. Conventionaltechniques involved measuring the auxiliary output voltage to controlthe field current. However, high nominal auxiliary output voltagesrequire voltage isolation measures to prevent disruption of low voltagecircuitry by the high voltage measurement. The example controller 110 ofFIG. 1 controls the weld voltage using a voltage-controlled (e.g.,constant voltage) control method (e.g., instead of a current controlledor constant current control method). The controller 110 uses the opencircuit weld voltage when the weld output is not being used to controlthe auxiliary power output. For example, if a droop in the weld opencircuit voltage is identified, the controller 110 assumes a similar dropin the auxiliary output voltage and increase the field current to reduceor eliminate the droop at the auxiliary power. Thus, the controller 110improves the auxiliary output voltage by reducing voltage drooping underload without requiring high voltage isolation techniques.

FIG. 2 is a flowchart illustrating example machine readable instructions200 which may be executed to implement the control circuitry 70 of FIG.1 to regulate an auxiliary power voltage of the power system 12 based ona weld power open circuit voltage of the power system 12.

At block 202, the control circuitry 70 determines whether the weld poweris being used. For example, the control circuitry 22 may measure theweld output voltage and/or the weld current to determine whether thewelding output is active. If weld power is being used (block 202), atblock 204 the control circuitry 70 regulates the weld power using awelding voltage feedback (e.g., the feedback 114 of FIG. 1 ).

When the weld power is not being used (block 202), at block 206, thecontrol circuitry 70 determines whether auxiliary power is being used.For example, the control circuitry 70 may measure the auxiliary currentor another measure of whether the auxiliary power is under load. Ifauxiliary power is not being used (block 206), control returns to block202.

If auxiliary power is being used (block 206), at block 208 the controlcircuitry 70 samples an open circuit voltage of the welding output(e.g., the feedback 114). For example, the control circuitry 70 mayreceive an output of a welding voltage sensor.

At block 210 the control circuitry 70 determines whether the weldingopen circuit voltage is less than a lower threshold voltage. The lowerthreshold voltage may be selected to correspond to a load at theauxiliary output that is causing a voltage droop. If the welding opencircuit voltage is less than a lower threshold voltage (block 210), atblock 212 the control circuitry 70 controls the generator 104 toincrease the auxiliary power voltage (e.g., by increasing the fieldcurrent). Control returns to block 202.

When the welding open circuit voltage is not less than the lowerthreshold (block 210), at block 214 the control circuitry 70 determineswhether the welding open circuit voltage is greater than an upperthreshold voltage. The upper threshold voltage may be selected toindicate that the welding voltage is approaching an unsafe voltage level(e.g., 113V) but leaving sufficient time to reduce the voltage bycontrolling the generator, rather than tripping a shutoff circuit. Whenthe welding open circuit voltage is greater than an upper thresholdvoltage (block 214), at block 216 the control circuitry 70 controls thegenerator 104 to decrease the auxiliary power voltage (e.g., bydecreasing the field current). If the welding open circuit voltage isnot greater than an upper threshold voltage (block 214), or afterdecreasing the auxiliary power voltage (block 216), control returns toblock 202.

FIG. 3A is a block diagram of an example redundant protection circuit300 to provide overvoltage and/or reverse polarity detection to anauxiliary DC output port. The redundant protection circuit 300 of FIG.3A may be implemented in the auxiliary power circuit 105 of FIG. 1 thatprovides DC output power for general purpose use (e.g., 12V). Theredundant protection circuit 300 is connected between power conditioningcircuitry 302 that converts power from the generator 104 to theauxiliary power, and provides two circuits capable of cutting off powerto auxiliary output terminals 304 in the event of a fault condition.

As illustrated in FIG. 3A, the redundant protection circuit 300 includesrelays 306 a, 306 b, relay controls 308 a, 308 b, overvoltage detectors310 a, 310 b, and polarity detectors 312 a, 312 b. The relays 306 a, 306b are controlled by the relay controls 308 a, 308 b to open or close acircuit between the power conditioning circuitry 302 and the outputterminals 304. When a fault, such as a reverse polarity fault or anovervoltage fault, is detected, one or both of the relays 306 a, 306 bare opened to cut off power to the output terminals 304. In some cases,the redundant protection circuit 300 may be restarted to reset a faultcondition. If the fault occurs after a restart of the circuit 300, amore serious fault may be present that requires servicing of the powersystem 100.

The overvoltage detectors 310 a, 310 b measure the voltage across theterminals 304 and identify a fault if, for example, the voltage exceedsa threshold voltage. The polarity detectors 312 a, 312 b determine thepolarity of a connection made between the terminals 304 and an outputdevice, such as a battery to be charged. The polarity detectors 312 a,312 b identify the polarity of the voltage at the terminals. If there isno polarity present (e.g., a non-voltage-generating device isconnected), the polarity detectors 312 a, 312 b may not detect apolarity. The example polarity detectors 312 a, 312 b detect a faultwhen an incorrect polarity is present, but do not detect a fault if nopolarity is detected.

FIG. 4 is an example truth table 400 for the polarity detectors 312 a,312 b of FIG. 3A. The truth table 400 illustrates a number of states 402of the polarity detectors 312 a, 312 b, each of which correspond to apolarity fault state (normal or fault) and output signals to theovervoltage detectors 310 a, 310 b. In the truth table 400, a detectedvoltage over a threshold of +0.5V (“Battery voltage input >0.5V) is anormal state, while a battery detected voltage less than the thresholdof +0.5V (“Battery voltage input <0.5V”), whether a negative voltage ora low positive voltage, is a fault state. The table 400 includes batteryvoltage input conditions 404, 406 corresponding to the polaritydetectors 312 a, 312 b, and circuit fault conditions 408, 410corresponding to the polarity detectors 312 a, 312 b. The circuit faultconditions 408, 410 indicate whether a fault has occurred in thepolarity detectors 312 a, 312 b that causes the output of the faultedpolarity detectors 312 a, 312 b to be either always “on” or always“off.”

Combinations of the conditions 404-410 cause one or both of the polaritydetectors 312 a, 312 b to control the output to the overvoltage circuits(column 412), a condition of the polarity detectors 312 a, 312 b (e.g.,column 414, either “normal” or “fault”), and the signal output to theovervoltage detectors 310 a, 310 b (e.g., column 416, either “on” toindicate that the polarity detectors 312 a, 312 b are permitting theauxiliary output to be enabled, or “off” to indicate that the auxiliaryoutput is to be disabled via the relays 306 a, 306 b). The overvoltagedetectors 310 a, 310 b of FIG. 3A are configured to disable the relays306 a, 306 b via the relay controllers 308 a, 308 b when an “off” signalis received from the polarity detectors 312 a, 312 b.

FIG. 5 is an example truth table 500 for the overvoltage detectors 310a, 310 b of FIG. 3A. The truth table 500 illustrates a number of states502 of the overvoltage detectors 310 a, 310 b. Each of the states 502correspond to an overvoltage fault state (normal or fault) and outputsignals to the relay controllers 308 a, 308 b. The states 502 of FIG. 5require that the input from the polarity detectors 310 a, 310 b is “on.”In the truth table 500, a detected voltage less than an overvoltagethreshold is a normal state, and a detected voltage greater than theovervoltage threshold is a fault state. The table 500 includes batteryvoltage input conditions 504, 506 corresponding to the overvoltagedetectors 310 a, 310 b, and circuit fault conditions 508, 510corresponding to the overvoltage detectors 310 a, 310 b. The circuitfault conditions 508, 510 indicate whether a fault has occurred in theovervoltage detectors 310 a, 310 b that causes the output of the faultedovervoltage detectors 310 a, 310 b to be either always “on” or always“off.”

Combinations of the conditions 504-510 cause one or both of theovervoltage detectors 310 a, 310 b to control the output to the relaycontrollers 308 a, 308 b (column 512), a condition of the overvoltagedetectors 310 a, 310 b (e.g., column 514, either “normal” or “fault”),and the signal output to the relay controllers 308 a, 308 b (e.g.,column 516, either “on” to indicate that the overvoltage detectors 310a, 310 b are permitting the auxiliary output to be enabled, or “off” toindicate that the auxiliary output is to be disabled via the relays 306a, 306 b).

Returning to FIG. 3B, this figure is a block diagram of an exampleredundant protection circuit 320 to provide overvoltage protection anddetection to a welding output port. The example redundant protectioncircuit 320 is connected between weld power conditioning circuitry 322and weld output terminals 324 of the power system 100 of FIG. 1 . Theredundant protection circuit 320 of FIG. 3B may be implemented in theauxiliary power circuit 105 of FIG. 1 that provides DC output power forgeneral purpose use (e.g., 12V). The redundant protection circuit 300 isconnected between power conditioning circuitry 302 that converts powerfrom the generator 104 to the auxiliary power, and provides two circuitscapable of cutting off power to auxiliary output terminals 304 in theevent of a fault condition.

The redundant protection circuit 320 includes relays 326 a, 326 b whichare controlled by respective relay controls 328 a, 328 b. The relaycontrols 328 a, 328 b control the relays 326 a, 326 b based on inputsfrom weld voltage detectors 330 a, 330 b. The weld voltage detectors 330a, 330 b measure the voltage across the weld output terminals 324 todetermine whether a weld output overvoltage condition is occurring.

FIG. 6 is an example truth table 600 for the weld voltage detectors 330a, 330 b of FIG. 3B. The truth table 600 illustrates a number of states602 of the weld voltage detectors 330 a, 330 b. In the truth table 600,weld output peak voltages are fed back into the controller 114 andcompared to a reference voltage by the controller 114. When the peakweld voltages go above a threshold (e.g., 110V), the controller 110multiplies the difference between the actual output voltage and thereference voltage by a gain value, and subtracts the result from thecommand. The controller 110 thereby reduces the output of the generator104 by lowering the field current in the rotor. The reduced output inthe generator 104 keeps the weld output voltage peaks below 110V. Thecontroller 110 reduce the likelihood of the weld voltages exceeding a113V safe peak maximum, and reduces instances of the hardware redundantcircuits from experiencing nuisance trips (e.g., tripping the system andcutting off power without a serious fault, posing a nuisance to the userwithout substantially improving safety). Without the controller 110“folding back” on the output, peak weld voltages will occur outside ofnormal operating conditions, that will trip the redundant hardwarecircuits.

Each of the states 602 correspond to an overvoltage fault state (normalor fault) and output signals to the relay controllers 328 a, 328 b. Inthe truth table 600, a detected weld voltage less than an overvoltagethreshold is a normal state, and a detected weld voltage greater thanthe overvoltage threshold is a fault state. The table 600 includes weldvoltage input conditions 604, 606 corresponding to the weld voltagedetectors 330 a, 330 b, and circuit fault conditions 608, 610corresponding to the weld voltage detectors 330 a, 330 b. The circuitfault conditions 608, 610 indicate whether a fault has occurred in theweld voltage detectors 330 a, 330 b that causes the output of thefaulted weld voltage detectors 330 a, 330 b to be either always “on” oralways “off.”

Combinations of the conditions 604-610 cause one or both of the weldvoltage detectors 330 a, 330 b to control the output to the relaycontrollers 328 a, 328 b (column 612), a condition of the weld voltagedetectors 330 a, 330 b (e.g., column 614, either “normal” or “fault”),and the signal output to the relay controllers 328 a, 328 b (e.g.,column 616, either “on” to indicate that the overvoltage detectors 310a, 310 b are permitting the auxiliary output to be enabled, or “off” toindicate that the auxiliary output is to be disabled via the relays 326a, 326 b).

FIGS. 7A, 7B, and 7C show a flowchart representative of example machinereadable instructions 700 which may be executed to implement the controlcircuitry 70 of FIG. 1 to automatically control a battery chargercircuit, such as the auxiliary output 105 of FIG. 1 .

At block 702, the controller 110 disables the battery charger output.Disabling the battery charger output may serve as a default state untilthe battery charger output is to be enabled. At block 704, thecontroller 110 determines whether a connection to a battery chargeroutput is present. If a connection to the battery charger output is notpresent (block 704), control returns to block 704 to wait for aconnection to a battery charger output.

When a connection to the battery charger output is present (block 704),at block 706 the controller 110 samples a battery output voltage andpolarity. For example, the battery output voltage and polarity may bemeasured at the auxiliary output. At block 708, the controller 110determines whether the minimum voltage (e.g., 0.1V) and correct polarityare present at the battery output terminals (e.g., based on the sampledbattery output voltage and polarity). If the minimum voltage and/or thecorrect polarity are not present (block 708), control returns to block702.

When the minimum voltage and correct polarity are present (block 708),at block 710 the controller 110 determines the commanded battery outputvoltage. For example, the controller 110 may determine that thecommanded battery output voltage. At block 712, the controller 110determines whether the battery output voltage is greater than a batteryreference voltage. An example battery reference voltage is based on atarget battery charging voltage (e.g., 14V). If the battery outputvoltage is greater than a battery reference voltage (block 712), atblock 714 the controller 110 determines whether a field current in thegenerator 104 is at least a threshold field current. An examplethreshold field current is 0.5 A, which is a current below which abattery charger may be considered to be trickle charging.

If the field current is at least the threshold field current (e.g., 0.5A) (block 714), at block 716 the controller 110 disables the batteryoutput and locks out a battery charge control. For example, thecontroller 110 may disconnect the battery output to prevent overchargingor other hazardous conditions, as well as preventing user controls ofthe battery charging output (e.g., disabling user controls such asvoltage controls, on/off switches, and/or other battery charging outputcontrols). The controller 110 permits resetting of the battery chargecontrol via a user control and/or via a reset of the entire power system100.

At block 718, the controller 110 determines whether the battery chargecontrol is reset. For example, the controller 110 may identify whether auser has triggered a battery charge control reset mechanism. If thebattery charge control is not reset (block 718), control loops to block716 to continue disabling the battery output. When the battery chargecontrol is reset (block 718), or if the field current is not at leastthe threshold field current (block 714), at block 720 the controller 110resets the battery charge circuit. After resetting the battery chargecircuit 720 and/or if the minimum voltage and/or the correct polarityare not present at the battery output terminals, control returns toblock 702.

Turning to FIG. 7B, if the battery output voltage is not greater thanthe battery reference voltage (block 712), at block 722 the controller110 determines whether a difference between the commanded output voltageand the battery output voltage (e.g., commanded output voltage−batteryoutput voltage) is greater than a threshold difference voltage and thegenerator field current is at least an upper threshold field current(e.g., a maximum field current). The threshold difference may be a smallvoltage, such as 0.1V, to enable the controller 110 to determine whetherthe battery is nearly fully charged for a battery conforming to expectedbattery characteristics.

If the difference between the commanded output voltage and the batteryoutput voltage is greater than the threshold difference voltage and thegenerator field current is at least the upper threshold field current(block 722), at block 724 the controller 110 automatically sets thegenerator 104 to a “Crank Assist” mode and controls the battery chargercircuit in the “Crank Assist” mode. The “Crank Assist” mode permits thebattery charger to provide a substantial current to crank an engine orprovide current for another large load. The change to the “Crank Assist”mode is automatic in that the controller 110 switches from a defaultmode, a charging mode, or another mode to the “Crank Assist” modewithout user intervention. At block 726, the controller 110 determineswhether the field current in the generator 104 is at least the upperthreshold field current (e.g., at a maximum field current) for at leasta threshold time (e.g., 20 seconds or some other time). If the fieldcurrent in the generator 104 is not at least the upper threshold fieldcurrent (e.g., at a maximum field current) and/or is at least the upperthreshold field current for less than a threshold time (block 726),control returns to block 722. If the field current in the generator 104is at least the upper threshold field current for at least the thresholdtime (block 726), control returns to block 702 of FIG. 7A. Additionallyor alternatively, the controller 110 may receive input from a button orother user interface device that enables a user to set the controller110 to the “Crank Assist” mode manually. The Crank Assist mode caused bythe user input may be temporary, after which the controller 110 returnsto a normal charge mode or to the last mode that the controller 110 wasin prior to the user input.

The controller 110 determines whether the difference between thecommanded output voltage and the battery output voltage is greater thanthe threshold difference voltage, and the generator field current isless than the upper threshold field current and greater than a lowerthreshold field current (block 728). If the difference between thecommanded output voltage and the battery output voltage is greater thanthe threshold difference voltage, and the generator field current isless than the upper threshold field current and greater than a lowerthreshold field current (block 728), at block 730 the controller 110automatically sets the generator 104 to a “Boost” mode to increasevoltage used as a reference voltage for controlling the battery chargeroutput. After the controller 110 sets the generator 104 to the Boostmode, control returns to block 722.

Turning to FIG. 7C, if the difference between the commanded outputvoltage and the battery output voltage is less than the thresholddifference voltage and the generator field current is less than a lowerthreshold field current (block 732), at block 734 the controller 110automatically sets the generator 110 to “Trickle” mode and controls thebattery charger circuit in the “Trickle” mode. At block 736, thecontroller 110 determines whether the difference between the commandedoutput voltage and the battery output voltage is less than the thresholdvoltage for at least a threshold time. If the difference between thecommanded output voltage and the battery output voltage is less than thethreshold voltage for at least a threshold time (block 736), controlreturns to block 702.

If the difference between the commanded output voltage and the batteryoutput voltage is at least the threshold difference voltage and thegenerator field current is less than the lower threshold field current(block 732), in block 738 the controller 110 sets the generator 104 to a“Charge” mode and controls the battery charger circuit in the “Charge”mode. Control then returns to block 722.

FIG. 8 is a flowchart illustrating example machine readable instructions800 which may be executed to implement the controller 110 of FIG. 1 tocontrol a generator field current. The instructions 800 may be executedto reduce or prevent overvoltage conditions from causing a fault. Thefield current may be for the weld voltage of the welding output. Atblock 802, the controller 110 controls the field current of thegenerator 104 using a commanded voltage. At block 804, the controller110 determines whether the weld peak voltage is greater than a thresholdvoltage. For example, the threshold voltage may be 110V for a maximumpermissible voltage of 113V. If the weld peak voltage is not greaterthan the threshold voltage (block 804), control returns to block 802.

If the weld peak voltage is greater than a threshold voltage (block804), at block 806 the controller 110 sets the error as a differencebetween the weld peak voltage and the threshold voltage. At block 808,the controller 110 multiplies the calculated error by a gain factor todetermine an adjustment. At block 810, the controller 110 subtracts theadjustment from the commanded voltage. Control returns to block 802.

FIG. 9A illustrates example functions of multiple-function LEDs that maybe used on the service pack of FIG. 1 to provide information to anoperator with a reduced number of LEDs. FIG. 9B illustrates examplefunctions of multiple-function LEDs that may be used on the service packof FIG. 1 to provide information to an operator with a reduced number ofLEDs. In the examples of FIGS. 9A and 9B, the multiple-function LEDsenable additional information to be provided to operators of the powersystem 100.

The present methods and systems may be realized in hardware, software,and/or a combination of hardware and software. The present methodsand/or systems may be realized in a centralized fashion in at least onecomputing system, or in a distributed fashion where different elementsare spread across several interconnected computing systems. Any kind ofcomputing system or other apparatus adapted for carrying out the methodsdescribed herein is suited. A typical combination of hardware andsoftware may include a general-purpose computing system with a programor other code that, when being loaded and executed, controls thecomputing system such that it carries out the methods described herein.Another typical implementation may comprise one or more applicationspecific integrated circuit or chip. Some implementations may comprise anon-transitory machine-readable (e.g., computer readable) medium (e.g.,FLASH memory, optical disk, magnetic storage disk, or the like) havingstored thereon one or more lines of code executable by a machine,thereby causing the machine to perform processes as described herein. Asused herein, the term “non-transitory machine-readable medium” isdefined to include all types of machine readable storage media and toexclude propagating signals.

As utilized herein the terms “circuits” and “circuitry” refer tophysical electronic components (i.e. hardware) and any software and/orfirmware (“code”) which may configure the hardware, be executed by thehardware, and or otherwise be associated with the hardware. As usedherein, for example, a particular processor and memory may comprise afirst “circuit” when executing a first one or more lines of code and maycomprise a second “circuit” when executing a second one or more lines ofcode. As utilized herein, “and/or” means any one or more of the items inthe list joined by “and/or”. As an example, “x and/or y” means anyelement of the three-element set {(x), (y), (x, y)}. In other words, “xand/or y” means “one or both of x and y”. As another example, “x, y,and/or z” means any element of the seven-element set {(x), (y), (z), (x,y), (x, z), (y, z), (x, y, z)}. In other words, “x, y and/or z” means“one or more of x, y and z”. As utilized herein, the term “exemplary”means serving as a non-limiting example, instance, or illustration. Asutilized herein, the terms “e.g.,” and “for example” set off lists ofone or more non-limiting examples, instances, or illustrations. Asutilized herein, circuitry is “operable” to perform a function wheneverthe circuitry comprises the necessary hardware and code (if any isnecessary) to perform the function, regardless of whether performance ofthe function is disabled or not enabled (e.g., by a user-configurablesetting, factory trim, etc.).

The present methods and/or systems may be realized in hardware,software, or a combination of hardware and software. The present methodsand/or systems may be realized in a centralized fashion in at least onecomputing system, or in a distributed fashion where different elementsare spread across several interconnected computing systems. Any kind ofcomputing system or other apparatus adapted for carrying out the methodsdescribed herein is suited. A typical combination of hardware andsoftware may be a general-purpose computing system with a program orother code that, when being loaded and executed, controls the computingsystem such that it carries out the methods described herein. Anothertypical implementation may comprise an application specific integratedcircuit or chip. Some implementations may comprise a non-transitorymachine-readable (e.g., computer readable) medium (e.g., FLASH drive,optical disk, magnetic storage disk, or the like) having stored thereonone or more lines of code executable by a machine, thereby causing themachine to perform processes as described herein.

While the present method and/or system has been described with referenceto certain implementations, it will be understood by those skilled inthe art that various changes may be made and equivalents may besubstituted without departing from the scope of the present methodand/or system. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the presentdisclosure without departing from its scope. Therefore, the presentmethod and/or system are not limited to the particular implementationsdisclosed.

What is claimed is:
 1. A power system, comprising: a generator toprovide electrical power based on mechanical power received from anengine, the electrical power comprising welding-type power andnon-welding power; a controller to control the generator or the engineto increase or decrease a voltage of the non-welding power based on avoltage measurement of the welding-type power; and an overvoltageprotection circuit comprises redundant circuits configured toselectively disable the non-welding power from the generator when thevoltage measurement exceeds a first threshold voltage.
 2. The powersystem as defined in claim 1, wherein the controller is to decrease thevoltage of the non-welding power when the voltage measurement of thewelding-type power exceeds a third threshold.
 3. The power system asdefined in claim 2, wherein the overvoltage protection circuit is todisable the welding-type power when the voltage measurement exceeds asecond threshold, the second threshold being a higher voltage than thefirst threshold.
 4. The power system as defined in claim 3, wherein theredundant circuits are further configured to selectively disconnect thewelding-type output from the generator.
 5. The power system as definedin claim 1, further comprising a voltage sensor to measure an opencircuit voltage for a welding-type output and to provide a signalrepresentative of the open circuit voltage to the controller as thevoltage measurement of the welding-type power.
 6. The power system asdefined in claim 1, wherein the controller is to control the generatorto increase the voltage of the non-welding power by increasing a fieldcurrent of the generator.
 7. The power system as defined in claim 1,wherein the controller is to control the generator to decrease thevoltage of the non-welding power by decreasing a field current of thegenerator.
 8. The power system as defined in claim 1, wherein thecontroller is to control the generator or the engine to increase ordecrease the voltage of the non-welding power when a welding-type outputis not providing the welding-type power.
 9. The power system as definedin claim 1, wherein the welding-type power and the non-welding power areconfigured to receive the electrical power via a same field winding inthe generator.
 10. The power system as defined in claim 1, wherein thecontroller is electrically isolated from the non-welding power.
 11. Amethod, comprising: providing non-welding electrical output from anengine-powered electrical generator to an output device; measuring avoltage of a welding-type output provided by the electrical generator;and controlling the generator or the engine, using redundant circuits ofan overvoltage protection circuit, to selectively disable thewelding-type output or the non-welding output of the electricalgenerator based on the voltage measurement of the welding-type outputexceeding a first threshold voltage.
 12. The method as defined in claim11, wherein the controlling of the generator or the engine comprisesdecreasing the voltage of the non-welding output when the voltagemeasurement of the welding-type output exceeds a first threshold. 13.The method as defined in claim 12, further comprising disabling, usingthe overvoltage protection circuits, the welding-type output when thevoltage measurement exceeds a second threshold, the second thresholdbeing a higher voltage than the first threshold.
 14. The method asdefined in claim 13, wherein the disabling of the welding-type output orthe non-welding output comprises selectively disconnecting, via the oneor more circuits, the welding-type output or the non-welding type outputfrom the generator.
 15. The method as defined in claim 11, wherein themeasuring of the voltage of the welding-type output comprises measuringan open circuit voltage of the welding-type output and providing asignal representative of the open circuit voltage to a control circuitas the voltage measurement of the welding-type power.
 16. The method asdefined in claim 11, further comprising controlling the generator toincrease the voltage of the non-welding output by increasing a fieldcurrent of the generator.
 17. The method as defined in claim 11, furthercomprising controlling the generator to decrease the voltage of thenon-welding output by decreasing a field current of the generator. 18.The method as defined in claim 11, further comprising disabling at leastone of the welding-type output or the non-welding output when thevoltage measurement exceeds a threshold.
 19. The method as defined inclaim 11, wherein the providing of the non-welding output comprisesproviding electrical power for the non-welding output from a same fieldwinding in the generator as the welding-type output.